The present invention concerns equipment for optical measurement of the shape of oblong objects.
When the shape of oblong objects, e.g., boards, is measured optically, a difficulty arises in the fact that the geometrical shape of the objects to be measured differs substantially from the shape of the image area (e.g., square) of the measuring instrument. If the entire object to be measured fits inside the picture area, the relative dimensional accuracy of its width dimension is approximately one order of magnitude inferior to the relative dimensional accuracy of the length dimension.
Attempts have been made to resolve this problem, e.g., several cameras are fitted along a line in the longitudinal direction of the object to be measured. However, a high number of apparatuses are required as well as the difficulty of joining the images together.
Another prior-art mode is to depict an object moving in the field of vision as several subsequent pictures. A drawback of this solution is providing a sufficiently long undisturbed run for the object.